1. Field of the Invention
The present invention relates to the shipment of food products, such as grain. More particularly, the present invention relates to the fumigation of such food products during the transport of the food product in a bulk material container. Additionally, the present invention relates to rail cars, such as hopper cars, which require the use of a fumigant for treating a food product contained within the hopper car.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Fumigant pesticides routinely are used to protect grains and legumes from insect damage during transport and storage. Before 1986, carbon tetrachloride and carbon disulfide mixtures were the primary fumigants used during rail transport. When these products were banned by the U.S. Environmental Protection Agency, fumigation using phosphorus and sulfur compounds increased. Aluminum phosphide, which is highly insecticidal, has been used increasingly by the grain industry. Aluminum phosphide pellets, deposited into a loaded boxcar, react with moisture in the gain to create the toxic gas phosphine. This reaction can occur within five minutes. The U.S. Department of Transportation requires that, after a loaded car is fumigated, it should remain out of transit for 48 hours. Once the gas completely dissipates, the food product is nontoxic.
Fumigants, such as aluminum phosphide, can liberate toxic gases that are rapidly absorbed through the respiratory tract. Symptoms may begin immediately and can include fatigue, headache, nausea, vomiting, abdominal pain, cough, and shortness of breath. Acute poisoning, such as occurs after inhalation of phosphine, can lead to pulmonary edema, central nervous system depression, toxic myocarditis, and circulatory collapse. As such, throughout the treatment of grains during transport, it is of increasing importance to minimize the amount of contact between the fumigant and the workers that may be handling such a fumigant. It is also important to avoid the dispersion of such gases throughout the environment.
Railroad hopper cars and tank cars carrying food items such as flour, corn syrup or other food products are sometimes treated during shipment to prevent contamination by insects or other pests. This is particularly true where temperatures over 50° F. are expected to be encountered. One way this has been done is by fumigating the car interior. Fumigant is introduced by means of packages which are kept in field containers until a shipper is ready to use them. In the past, the fumigant packages have been simply taped to corrugated cardboard panels or disks that are placed over the hatch opening or coaming, with the fumigant facing down in the car. A plastic cover is taped over the top of the cardboard, and then the hatch cover is closed. Exposure of the fumigant package to air causes a chemical reaction which releases a fumigant, such as a hydrogen phosphide, into the car.
The corrugated cardboard mounting method used in the past leads to several problems. Taping the fumigant packages to the cardboard is a handling problem. Installing the cardboard in the hatch openings is laborious and slow. The cardboard panels or disks present disposal problems. The corrugations of the cardboard present inviting hiding places for insects which, although they are killed by the fumigant, can be a contamination hazard upon unloading. That is, they tend to fall out of the corrugations into the interior of the railcar when the cardboard is removed for unloading. Additionally, such fumigant packages may accidentally release from the cardboard during transport. As a result, the material of the fumigant packages can come into direct contact with grain, or other bulk material, within the interior of the rail car so as to contaminate the product within the rail car. Once again, this prior technique of affixing the fumigant packages to the cardboard panels is time consuming, inefficient, ineffective and present potential safety problems. As such, a need has developed so as to avoid the use of the cardboard mounting technique.
In the past, various patents and patent publications have published relative to the fumigation of containers of food product, such as grain and legumes. For example, U.S. Pat. No. 2,857,630, issued on Oct. 28, 1958 to F. S. Bishop, describes a system for substantially eliminating insect infestation in cars, bins, and the like. In particular, this patent describes a fumigant composition which includes carbon tetrachloride, carbon disulfide and petroleum ether. This fumigation product is introduced directly into the grain within the car or bin.
U.S. Pat. No. 3,041,684, issued on Jul. 3, 1962 to Dawson et al., describes a process for the fumigation of grains. In particular, this fumigation technique is used in association with a grain storage structure having an opening at the top and an air duct at the bottom. An air-tight bonnet of flexible sheet material is releasably secured over the top opening. The bonnet has a tubular arm projecting outwardly therefrom. An air-tight plenum chamber is releasably secured to the fan so as to form a air-tight seal. The fumigation is directed into the plenum chamber so as to properly fumigate grain being stored in the grain storage structure.
U.S. Pat. No. 3,097,916, issued on Jul. 16, 1963 to Dawson et al., describes a similar apparatus to that of U.S. Pat. No. 3,041,684.
U.S. Pat. No. 5,055,277, issued on Oct. 8, 1991 to L. H. Gunn, describes a fumigating apparatus for shipping containers. This fumigating apparatus includes a long, flexible chain or string of gas-permeable solid fumigant holders, and a long, rigid pole or thrusting member. The holders are joined at predetermined intervals within the string by means of pre-cut lengths of rope or cord. The pole is attached to a distal-most one of the holders and is used to thrust the string of holders into the container through its open end and into the headspace above the commodity to be fumigated. The pole is then detached from the string and removed from the container to leave the string in place.
U.S. Pat. No. 5,239,772, issued on Aug. 31, 1993 to Burian et al., provides a railroad car pesticide device holder which has a frame resting in a hatch coaming. The frame has a gas-permeable underside support sheet and an impervious upper membrane. Pesticide devices, such as fumigant packages, rest between the support sheet and membrane. A separator is provided to prevent contact between the fumigant packages.
U.S. Pat. No. 7,908,791, issued on Mar. 22, 2011 to K. G. Brash, discloses a fumigation apparatus that includes a conventional shipping container. A partition divides the container into a fumigation chamber and a control room. A means is arranged to supply gas into the fumigation chamber. A control means is located in the control room so as to control the flow of gas into the fumigation chamber. An extraction means is provided so as to remove gas from the fumigation chamber.
U.S. Patent Publication No. 2008/80251514, published on Oct. 16, 2008 to Fitzpatrick et al., shows a shipping container which has a pair of a gas portals fitted thereto. One portal is located in an uppermost stiffening groove or recess positioned in an end door of the container, and a second portal being located in a lowermost stiffening groove or recess located in the same end door. The uppermost portal is coupled to a fumigant introducing means in the form of a fumigant tank containing a source of liquefied fumigant reagent, a heater, an inlet fan and a gas hose located between each of these items. A further hose is connected to the uppermost portal.
U.S. Patent Publication No. 2012/0102818, published on May 3, 2012 to Rogacki et al., teaches the fumigation of containerized cargo. A portable fumigation containment door is installed in covering relationship with main rear opening of a cargo container. An inflatable gasket extends around the perimeter of the containment door and is inflated to create an airtight seal between the cargo container and the containment door. The door is provided with a series of connection ports for receiving fumigant injection and sampling lines necessary for performing the fumigation process.
It is an object of the present invention to provide an apparatus and method for holding a fumigant container which avoids the need to tape the fumigant container to a corrugated cardboard sheet.
It is another object of the present invention to provide an apparatus and method for holding a fumigant container which is efficient to utilize.
It is another object of the present invention to provide an apparatus and method for holding a fumigant container that limits exposure of the fumigant to the worker.
It is still a further object of the present invention to provide an apparatus and method for holding a fumigant container that avoids inconsistent application of the fumigant to the material within the bulk material container.
It is a still a further object of the present invention to provide an apparatus and method for holding a fumigant container which distributes the fumes of the fumigant evenly.
It is still a further object of the present invention to provide an apparatus and method for holding a fumigant container which avoids contact between the fumigants and the bulk material with the container
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.